US President Joe Biden on Thursday directed US military airstrikes in eastern Syria against facilities belonging to what the Pentagon said were Iran-backed militia, in a calibrated response to rocket attacks against US targets in Iraq.
The strikes, which were first reported by Reuters, appeared to be limited in scope, potentially lowering the risk of escalation.
Biden's decision to strike only in Syria and not in Iraq, at least for now, also gives the Iraqi government some breathing room as it carries out its own investigation of a February 15 attack that wounded Americans.
"At President (Joe) Biden's direction, US military forces earlier this evening conducted airstrikes against infrastructure utilized by Iranian-backed militant groups in eastern Syria," Pentagon spokesman John Kirby said in a statement.
"President Biden will act to protect American and Coalition personnel. At the same time, we have acted in a deliberate manner that aims to de-escalate the overall situation in both eastern Syria and Iraq," Kirby said.
He added that the strikes destroyed multiple facilities at a border control point used by a number of Iranian-backed militant groups, including Kata'ib Hezbollah (KH) and Kata'ib Sayyid al-Shuhada (KSS).
A US official, speaking on the condition of anonymity, said the decision to carry out these strikes was meant to send a signal that while the United States wanted to punish the militias, it did not want the situation to spiral into a bigger conflict.
The official added that Biden was presented with a range of options and one of the most limited responses was chosen.
It was not immediately clear what damage was caused and if there were any casualties from the strike.
Retaliatory US military strikes have occurred a number of times in the past few years.
The rocket attacks on US positions in Iraq were carried out as Washington and Tehran are looking for a way to return to the 2015 nuclear deal abandoned by former US President Donald Trump.
It was not clear how, or whether, the strike might affect US efforts to coax Iran back into a negotiation about both sides resuming compliance with the agreement.
In the February 15 attack, rockets hit the US military base housed at Erbil International Airport in the Kurdish-run region killing one non-American contractor and injuring a number of American contractors and a US service member. Another salvo struck a base hosting US forces north of Baghdad days later hurting at least one contractor.
Rockets hit Baghdad's Green Zone on Monday which houses the US embassy and other diplomatic missions.
Earlier this week, the Kata'ib Hezbollah group, one of the main Iran-aligned Iraqi militia groups, denied any role in the rocket attacks.
Some Western and Iraqi officials say the attacks, often claimed by little-known groups, are being carried out by militants with links to Kata'ib Hezbollah as a way for Iranian allies to harass US forces without being held accountable.
Since late 2019, the United States has carried out high-profile strikes against the Kata'ib Hezbollah militia group in Iraq and Syria in response to sometimes deadly rocket attacks against US-led forces.
Under the Trump administration, the escalator back-and-forth stoked tensions, culminating in the US killing of Iranian military leader Qassem Soleimani and a retaliatory Iranian ballistic missile attack against US forces in Iraq last year.